Psalm 141:3 Set a guard, O Lord, over my mouth; keep watch over the door of my lips.
Controlling the words of your mouth are easier said than done, because something may slip out when you least expect it. The Psalmist asks the Lord to set a guard over his mouth, because he knows how difficult it is to accomplish it himself. Start the day in prayer asking the Lord to help you with your words. Pray during the day, then close the day in prayer. God will give directions for your daily activities because of prayer. Breakdowns in peoples lives invariable didn’t come all of a sudden, but usually occur because of small breakdowns in Bible reading and prayer over a period of time. The attitude of some is, “That won’t happen to me because I’m too strong a Christian.” Don’t believe it, because the enemy will be after you in a bigger way. Go back to the Word, then pray the Word, then expect the Lord to help you.
If you don’t want it - don’t say it. Your words are seeds you plant and then wonder where the crop comes from. Never again speak what you don’t expect to receive. A lot of things are opened by mistake, but none so often as the mouth.